Thanks a lot for your thoughts everyone: I really appreciate you all taking the time to respond - I'll continue my research with all the tips!
I would certainly love to enter the 'total emersion' school. For me, the voice is the 'purist' of instruments (and no - I'm not meaning to be provocative or impose that as any kind of absolute truth!). It is where my heart lies musically. There are so many shatteringly good instrumentalists around - fiddle, flute etc - I feel singers are less likely to be held in the same regard. Is there an assumption that singers somehow just have a 'gift' of voice, and don't work on this as their discipline? Just a thought.
The Trad English Course sounds just my cuppa tea - wish I was there... or they were here.... mmm wonder if they are into touring!